1. Field of the Invention
The invention refers to an aqueous solution of ascorbic acid.
2. Description of the Related Art
The technical use, in particular in personal hygiene and foodstuffs, and prophylactic application of the reductone, ascorbic acid, is often made more difficult in that the ascorbic acid is not sufficiently stable in aqueous solution. Consequently, in an aqueous ascorbic acid solution only about 70% of the added ascorbic acid is still present after 30 days.
Attempts have been made to improve the stability in that instead of ascorbic acid, one of its derivatives, for example sodium ascorbic phosphate or ascorbyl palmitate, has been employed. The content of this active substance is almost fully retained in aqueous solution over a long period of time. However, the derivative is many times more expensive than pure ascorbic acid. In addition, at higher concentrations the ascorbic acid derivatives tend to crystallize out and lead to colouration of the end product.
From the European Patent Specification 660676 a combination is known consisting of 0.1-2.0% by weight of an oil-soluble constituent which is preferably a colorizing carotenoid, 2-20% by weight of an emulsifier with an HLB value of 10-18 and 0.1-1.0% by weight of an antioxidation agent. The emulsifier can be Polysorbate 40 or 60 and ascorbic acid is one of the recommended antioxidation agents. With this technique, coloured clear and stable drinks for health care should be able to be produced. The stability of the ascorbic acid in the end product is however still not explained.
The object of the invention is to provide ascorbic acid in a fluid, water and fat-soluble and encapsulated form (e.g. gelatine capsule), which is stable over many months and is available in high concentration.
FIG. 1: Schematics and electron micrographs of the micelle formed using a 10% ascorbic acid solubilisate in water and in paraffin are illustrate.
FIG. 2: A graph showing the mean micelle radii of the xcex1-tocopherol solubilisate.
FIG. 3: A graph showing the mean micelle radii of the ⊕-carotene solubilisate.
FIG. 4: A graph showing the mean micelle radii of the retinol solubilisate.
FIG. 5: A electron micrograph image of a Vitamin A micelle.
FIG. 6: A electron micrograph image of Vitamin E micelles, an electron micrograph image of the substrate without micelles, and a graph showing the mean micelle radii of the Vitamin A and Vitamin E solubilisates in aqueous solution.